Rotary cutters are agricultural implements used for cutting large areas of vegetation, such as grass, weeds, shrubs, or the like. In general, a rotary cutter comprises a deck, which is supported above the ground by one or more wheels. The rotary cutter additionally includes one or more rotating blade assemblies that extend from a bottom of the deck. The blade assemblies each include one or more rotating blades configured to cut vegetation as the rotary cutter travels over the ground. Certain types of rotary cutters are configured to be pulled behind a heavy-equipment machine, such as a tractor. As such, rotary cutters are capable of traversing the ground on which the vegetation to be cut is present.
In previously used rotary cutters, the cutter blades used in the blade assemblies were commonly known to become locked in skewed orientations with respect to their respective blade assemblies. Such locking of the cutter blades in a skewed orientation inhibited cutting action. In addition, such previously-used cutter blades were often known to cause unwanted vibrations throughout the rotary cutters. The inventors of the present invention have determined that such problems were due, in part, to the previously-used cutter blades having low centers of gravity (the term “low” is used herein to mean located in a direction away from the deck of the rotary cutter and towards the ground when the blade assemblies extend from a bottom of the deck). As discussed herein, the term “center of gravity” is used to mean a point in or on the cutter blade that defines the cutter blade's center of mass.
In general, the center of gravity of previously-used cutter blades was generally positioned below a horizontal plane that bisected a height of the cutter blade (with the height being defined as a distance from a lowest point of the cutter blade to a highest point of the cutter blade). Such low centers of gravity were due, in part, to previously-used cutter blades being “vertically offset.” Specifically, free-ends of most previously-used cutter blades were positioned lower than (i.e., vertically-offset from) the proximal ends of the cutter blades, with the proximal ends being connected to the blade assemblies. Such vertically-offset cutter blades were thought to be beneficial because the free-ends of the cutter blades would not impact the blade assemblies (or the cutter deck) if the cutter blades were permitted to freely rotate with respect to the cutter assemblies. As such, vertically-offset cutter blades could avoid causing damage to the rotary cutter, to the blade assemblies, and to the cutter blades themselves. Nevertheless, such vertically-offset cutter blades have drawbacks. For example, because such cutter blades extend far below the deck of the rotary cutter, they are prone to come into contact with the ground and/or debris when the rotary cutter is in operation.